diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index e05f73e5e..6231fd88d 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -1579,6 +1579,32 @@ bool Tokenizer::tokenize(std::istream &code,
                 syntaxError(tok);
                 return false;
             }
+        } else if (Token::simpleMatch(tok, "if (")) {
+            bool macro = false;
+            unsigned int parlevel = 0;
+            for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) {
+                if (tok2->str() == "(")
+                    ++parlevel;
+                else if (parlevel > 0 && tok2->str() == ")") {
+                    --parlevel;
+                    if (parlevel == 0) {
+                        if (Token::Match(tok2, ") %var% [({]") && tok2->next()->isUpperCaseName())
+                            macro = true;
+                        else if (!macro)
+                            break;
+                    }
+                }
+                if (tok2->str() == ";")
+                    break;
+                if (tok2->str() == "{") {
+                    if (macro) {
+                        syntaxError(tok2);
+                        return false;
+                    } else {
+                        break;
+                    }
+                }
+            }
         }
     }
 
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index 6e3c5031e..d4135a612 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -770,6 +770,12 @@ private:
         const std::string code("void f() { if MACRO(); }");
         tokenizeAndStringify(code.c_str(), false);
         ASSERT_EQUALS("[test.cpp:1]: (error) syntax error\n", errout.str());
+
+        // #4668
+        errout.str("");
+        const char code2[] = "void f() { if (x) MACRO() {} }";
+        tokenizeAndStringify(code2, false);
+        ASSERT_EQUALS("[test.cpp:1]: (error) syntax error\n", errout.str());
     }
 
     void wrong_syntax_class_x_y() {